Welcome to L-Star!

The L-Star project is a single-board computer that you can build yourself, based on the venerable 6502 processor. But instead of ROM and I/O chips, it uses a Propeller microcontroller. The Propeller “bitbangs” the bus of the 6502 to make it think it’s in a computer that’s not actually there.

L-Star is not a replica for any specific machine: it can take on the identity of many early 6502 computers. It’s also not exactly an emulator, since it uses an actual 65C02. It’s something in between, which I call a “Software Defined Computer”: The software that runs on the Propeller determines how the 65C02 “sees the world”. Nevertheless, it’s still possible to connect real peripherals and real memory if the Propeller is not sufficient.

You can build L-Star on a breadboard, or on a Propeller Proto board, or in some other way. Or you can buy it as a kit from Tindie. The hardware design and the software are open source, available from my Github repo.

I’ve worked on L-Star since 2014 (and on its predecessor since 2011), but the website you see in front of you is relatively new and very much under construction, so there’s not much here yet. Please click on one of the categories above or below:

Learn: Learn how the 6502 works, how the Propeller works, and how they work together.

Build: Find out how to build your own L-Star: How to solder the L-Star Plus Kit, how you can build an L-Star on a breadboard, or on a piece of perforated board or a Propeller prototype board…

Use: Install one of the existing Software Defined Computer projects such as the Apple-1 or OSI Challenger, and use it to do something useful, or just play around.

Discover: Information and inspiration to help you use the L-Star for your own projects…

I hope you’ll have as much fun playing with L-Star as I had designing it!